checkboxGroupInput delete table output in a shiny app

Question

I'm creating a shiny app whose selections in the checkboxgroup return a table with filtered data after clicking on the actionbutton, as shown in the example below. My question is how do I include the functionality, after generating the table when I click again on any checkbox the tables are deleted until the user clicks on the actionbutton again.

library(shiny)
library(DT)
library(dplyr)

ui <- fluidPage(

      checkboxGroupInput(inputId = "checkboxGroup1", label = "checkboxGroup1", choices = list(5.0, 4.6)),
      checkboxGroupInput(inputId = "checkboxGroup2", label = "checkboxGroup2", choices = list(3.4, 3.6)),
      checkboxGroupInput(inputId = "checkboxGroup3", label = "checkboxGroup3", choices = list(0.2, 1.5)),
      checkboxGroupInput(inputId = "checkboxGroup4", label = "checkboxGroup4", choices = list("setosa", "virginica")),
      actionButton('action',label = 'action'),

      mainPanel(
          dataTableOutput("table1")
        )
    )


# Define server logic required to draw a histogram
server <- function(input, output) {
  
  filter_data <- eventReactive(input$action, {
    
    data <- iris
    
    Sys.sleep(5) #included to delay the output

    data %>% 
      {if (is.null(input$checkboxGroup1) == FALSE) filter(., Sepal.Length %in% input$checkboxGroup1) else .} %>% 
      {if (is.null(input$checkboxGroup2) == FALSE) filter(., Sepal.Width %in% input$checkboxGroup2) else .} %>% 
      {if (is.null(input$checkboxGroup3) == FALSE) filter(., Petal.Width %in% input$checkboxGroup3) else .} %>%
      {if (is.null(input$checkboxGroup4) == FALSE) filter(., Species %in% input$checkboxGroup4) else .}

  })
  
  output$table1 <- renderDataTable(
    filter_data()
  )
  
}

# Run the application 
shinyApp(ui = ui, server = server)

Edited: added 'Sys.sleep(5)' to delay the output. Just hiding the table would not solve this case, if the action button is pressed before the update.

Answer 1

Here's an option using shinyjs. First create a reactive expression that is dependent on all checkbox inputs. We can use shinyjs::hide to hide the DT anytime a checkbox is selected. Then use shinyjs::show to show the table when the action button is clicked.

Demo w/ updated basic UI

library(shiny)
library(DT)
library(dplyr)
library(shinyjs)

ui <- fluidPage(
    useShinyjs(), # include shinyjs here
    checkboxGroupInput(inputId = "checkboxGroup1", label = "checkboxGroup1", choices = list(5.0, 4.6)),
    checkboxGroupInput(inputId = "checkboxGroup2", label = "checkboxGroup2", choices = list(3.4, 3.6)),
    checkboxGroupInput(inputId = "checkboxGroup3", label = "checkboxGroup3", choices = list(0.2, 1.5)),
    checkboxGroupInput(inputId = "checkboxGroup4", label = "checkboxGroup4", choices = list("setosa", "virginica")),
    actionButton('action',label = 'action'),

    mainPanel(
        dataTableOutput("table1")
      )
)

# Define server logic required to draw a histogram
server <- function(input, output) {
  
  filter_data <- eventReactive(input$action, {
    data <- iris
    data %>% 
      {if (is.null(input$checkboxGroup1) == FALSE) filter(., Sepal.Length %in% input$checkboxGroup1) else .} %>% 
      {if (is.null(input$checkboxGroup2) == FALSE) filter(., Sepal.Width %in% input$checkboxGroup2) else .} %>% 
      {if (is.null(input$checkboxGroup3) == FALSE) filter(., Petal.Width %in% input$checkboxGroup3) else .} %>%
      {if (is.null(input$checkboxGroup4) == FALSE) filter(., Species %in% input$checkboxGroup4) else .}
  })
  
  obs_checkboxes = reactive({
    list(input$checkboxGroup1,input$checkboxGroup2,input$checkboxGroup3,input$checkboxGroup4)
  })

  observeEvent(obs_checkboxes(), {
    hide("table1")
  })
  
  observeEvent(input$action, {
    show("table1")
  })
  
  output$table1 <- renderDataTable(
    filter_data()
  )
}

# Run the application 
shinyApp(ui = ui, server = server)